Estimación de Cosecha de Maíz Forrajero (Zea mays L.) Mediante Índices Espectrales Derivados de LANDSAT-8 y SENTINEL-2

La estimación de cosecha basada en índices espectrales conforma un elemento de decisión importante para quienes participan en la actividad agrícola; sin embargo, muchas interrogantes sobre su utilidad aún persisten. Los objetivos de esta investigación fueron: 1) relacionar propiedades radiativas del maíz forrajero (MF) y producción de biomasa mediante imágenes LANDSAT-8 y SENTINEL-2; y 2) seleccionar el índice de vegetación (IV) con mejor desempeño que permita modelar el rendimiento del MF para condiciones similares. El estudio se realizó en el ciclo PV-2019 con mediciones morfológicas en distintas etapas de crecimiento del MF y mediante muestreos aleatorios destructivos a los 72 dds para determinar magnitud de biomasa en laboratorio; los datos de biomasa se relacionaron con valores de reflectancia e IV de LANDAT-8 y SENTINEL-2 para estimar rendimiento mediante regresión lineal múltiple; ocho IV (NDVI, TVI TTVI, RDVI, RVI, RATIO, SAVI, MSAVI2) se evaluaron mediante evaluaciones cruzadas con base en estadísticos clave. Los resultados del análisis de regresión múltiple indicaron que el mejor modelo (R2 = 0.66) se obtuvo con datos de imágenes SENTINEL-2 a partir de las bandas 3 (α3 = 0.54-0.57 µm) y 8 (α8= 0.78-0.90 µm) con estimadores βi muy significativos (P < 0.05); RDVI presentó el mejor desempeño debido a una buena relación espacial entre los valores digitales ráster y la producción de biomasa verde producida con una asociación del 75.41%; en tanto que los indicadores estadísticos fueron R2= 0.75 y CME=17; con ambos recursos (Modelos de Regresión Múltiple e IV) se pronosticó el rendimiento a los 72 dds en un rango de 10.7 – 57.01 Mg ha-1. La conclusión es que SENTINEL-2 superó a LANDSAT-8 como herramienta libre para la evaluación de cultivos y estimación de biomasa debido a una mejor resolución espacial y temporal

Análisis ecológico de un área de pago por servicios ambientales hidrológicos en el ejido La Ciudad, Pueblo Nuevo, Durango, México

In Mexico, the National Forestry Commission implements the payment for hydrological environmental services, whose objective is to reduce the rate of deforestation in critical areas for water recharging. Although the approved projects are followed up, there is no analysis of the benefits generated by this mechanism. Generating information for these evaluations plays a key role. The main objective of this research was to perform an ecological analysis of payment for hydrological environmental services beneficiary area in the common land La Ciudad, seven years after the allocation of support. The forest cover of the area, the state of the vegetation, the diversity of species and the quality of the water were analyzed. The results showed that the area has a considerable percentage of forest cover and acceptable biodiversity. In the analysis of water quality, contamination can occur, which is why more frequent monitoring is recommended.En México la Comisión Nacional Forestal implementa el pago por servicios ambientales hidrológicos, cuyo objetivo es reducir la tasa de deforestación en zonas críticas para recarga de agua. Aunque se da seguimiento a los proyectos aprobados, no se tiene un análisis de los beneficios que genera este mecanismo. Generar información para evaluar estos beneficios juega un papel clave. El objetivo principal de esta investigación fue realizar un análisis ecoló- gico de un área beneficiaria de pago por servicios ambientales hidrológicos del ejido La Ciudad, a siete años de la asignación del apoyo. Se analizó la cobertura forestal del área, el estado de la vegetación, la diversidad de especies y la calidad del agua. Los resultados mostraron que el área cuenta con un porcentaje considerable de cobertura forestal y niveles aceptables de biodiversidad. En análisis de calidad del agua mostró una posible contaminación por lo que se recomienda un monitoreo más recurrente

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research